As a service volume of the mobile Internet rapidly grows, a capacity problem of an LTE (Long Term Evolution, Long Term Evolution) communications system becomes increasingly noticeable, and there is an urgent need to improve spectral efficiency to enhance a network capacity. In this background, a full-duplex technology in which data transmission is performed by using an eNB (Enhanced Node B, evolved NodeB) attracts more attention. The full-duplex technology means that the eNB simultaneously sends downlink data and receives uplink data on a same frequency band and by using a same subframe, thereby doubling the spectral efficiency to enhance the network capacity.
Full-duplex transmission is initiated by the eNB. Therefore, before the initiation, the eNB needs to confirm that buffer and preparation statuses of a UE (User Equipment, user equipment) meet a requirement. However, this confirmation process can be completed only after the UE sends related signaling to the eNB. This definitely increases load of an entire system, easily leads to excessively high signaling overheads during data transmission, and increases a transmission delay.